Audible alarms and signals have long been used to notify people of a remote event. For example, doorbells provide a notification that someone is waiting outside of the door and oven timers provide a notification that a certain amount of time has expired. In addition, remote events can be monitored through the sound caused by the event itself. Baby monitors, for instance, allow a carer to react when their child is crying by transmitting sound from the baby's location to the carer's location. However, such devices are not as versatile as may be desirable.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known monitoring and notification apparatus.